Study of the Oxygen Transfer Efficiencies in the Different Methods Used in the Technique of Hypolimnetic Aeration

Abstract

Thermal stratification of lakes and reservoirs can result in substantial hypolimnetic oxygen depletion, which may have a negative impact on the cold-water fisheries, the drinking water treatment process, and water quality downstream of hydropower reservoirs. Several techniques of aeration are presented in this study, to describe their effectiveness in control of physical and chemical parameters, that compromising the balance ecological and the thermal stratification in water supplies. As a result, we demonstrate that the most efficient hypolimnetic aeration system is the bubble plume diffuser; although an accidental destratification may occur. In hypolimnetic aeration systems, the aeration system by bubble plume appears to be the most economic and perhaps the simplest among the systems used in Stanley lake (Colorado, U.S.A), even as other researches select Speece Cone aeration system, or the full airlift systems, or the TVA line diffuser. The purpose of this study is to show the oxygen transfer efficiencies in the different methods used in the technique of hypolimnetic aeration, and their effect on the preservation of the thermal stratification. As well, this study concentrate on the economic and technical sides associated to these aeration systems.

Influence of Aeration Pipe Length on Oxygen Mass Transfer Efficiency in Terms of Bubble Motion Flow Field

“…Compared with the aerators commonly used for microporous aeration, the linear microporous aeration system has been well applied by the Tennessee Valley Authority. The bubbles generated by this system have the characteristics of plume diffusion, and the efficiency of oxygen mass transfer in deep water is more than 90%. , However, when linear microporous aeration is applied to repair black and odorous water in rivers and lakes with a small water depth, the oxygen mass transfer efficiency is inhibited. The utilization rate of oxygen decreases with the decrease in water depth; when the water depth is 2–5 m, the utilization rate of oxygen is generally about 15%, which results in a large waste of aeration energy consumption.…”

Influence of Aeration Microporous Aperture on Oxygen Mass Transfer Efficiency in Terms of Bubble Motion Flow Field

“…Because of its advantages of simple operation and low cost, it has been widely used. Microporous aeration has the advantage of high oxygen utilization rate because of the smaller bubble size, which leads to its longer residence time and larger gas–liquid contact area with water, and it has been applied in the rehabilitation of various municipal and industrial wastewaters and has achieved good results. , Previous investigations showed that the water restoration effect is closely related to the oxygen mass transfer process. , The linear microporous hose aeration applied in Tennessee Valley has an oxygen utilization rate of over 90% in deep water; , however, the oxygen utilization rate is only about 15% with a relatively shallow water depth (2–5 m), which limits the application of the microporous aeration technology. Therefore, how to improve the oxygen mass transfer efficiency of microporous aeration is an urgent problem to be solved.…”

A hypolimnetic aeration system to meet the hypolimnetic oxygen demand by increasing the natural assimilation capacity of a reservoir

“…These studies are concerned at the first hand on the design of lab‐scale aeration equipment, the transfer of air to the water and the effects on the aeration of the water body. There are also review articles comparing different studies (Beutel and Horne, 1999; Mostefa et al ., 2012; Singleton and Little, 2006). Lab‐scale studies are followed by pilot‐scale implementations in the field and mathematical modelling approaches (Taggart and Mcqueen, 1982; Ashley et al ., 1987, 1991; Little, 1995; Burris et al ., 2002).…”